The objective of this project is to examine cancer incidence and mortality among populations exposed to varying amounts of ionizing and non-ionizing radiation. Groups from which useful data can be obtained include the Japanese A-bomb survivors, patients exposed to high-dose medical diagnostic radiation and to therapeutic radiation, workers with histories of occupational exposures to radiation, and the populations of SEER reporting areas with different levels of solar UV radiation. The listed project members all have individual research interests in radiation-induced cancer. One of the aims of establishing this new project is to provided a framework for increased interaction and cross-fertilization of ideas. BIBLIOGRAPHIC REFERENCES: McGregor, D.H., Land, C.E., Choi, K., Tokuoka, S., Liu, R.I., Wakabayashi, T. and Beebe, G.W.: Breast cancer incidence among atomic bomb survivors, Hiroshima and Nagasaki, 1950-69. J. Natl. Cancer Inst., in press, September 1977. Land, C.E., McGregor, D.H.: Temporal distribution of risk after exposure. Proceedings of the $ Third International Symposium on Detection and Prevention of Cancer. Vol. I, Chapter 8: Radiation-Induced Cancer. Marcel Dekker, NY, 1977. In press.